Glutaraldehyde is prepared on an industrial scale by the hydrolysis of 2-methoxy-3,4-dihydro-2H-pyran (MDP) in the presence of an acid catalyst and water. The crude hydrolysis product is distilled to produce a methanol overheads stream, a by-product of the reaction that is itself suitable for recycling and use in other industrial processes, and a tails product containing glutaraldehyde in water. Glutaraldehyde is an important chemical that is used, for example, as a biocide or in leather tanning.
In the known processes for glutaraldehyde manufacture, some of the unreacted MDP starting material is removed, along with the methanol by-product, by the distillation process. Although the amount is generally small, the presence of the MDP in the distilled methanol is undesirable for a number of reasons, including that yield of glutaraldehyde is reduced as a result of the MDP loss, and that the MDP is a contaminant of the methanol byproduct which, as noted above, is a material that is recyclable and useful in other industrial processes.
The invention addresses the foregoing shortcomings of the current glutaraldehyde production process.